Scientists flock to mysterious 'blue hole' off Florida's Gulf Coast

The phenomenon is located about 425 feet below the water's surface.

July 22, 2020, 5:48 PM

Scientists are flocking to Florida’s Gulf Coast for a glimpse of a mysterious 425-feet-deep "blue hole" on the ocean floor.

The glowing mystery hole, about 155 feet below the water’s surface, is similar to the sinkholes seen on solid land, according to the National Oceanic and Atmospheric Administration.

The site, dubbed the "Green Banana,” has been a hot topic for scientists and deep-sea explorers who've been hoping for a glimpse of the phenomenon from afar.

Surprisingly, the first reports of blue holes came from fishermen and recreational divers, not scientists or researchers. In general, the holes appear to host diverse biological communities full of marine life, including corals, sponges, mollusks, sea turtles and sharks.

NOAA scientists already have collected 17 water samples from the area surrounding the hole along with four sediment samples.

PHOTO: Scientists are flocking toward the coast of Florida to explore a mysterious "blue hole" on the ocean floor.
Scientists are flocking toward the coast of Florida to explore a mysterious "blue hole" on the ocean floor.
Mote Marine Laboratory via NOAA

Remarkably, they also discovered two dead but intact smalltooth sawfish, an endangered species, at the bottom of the hole, according to NOAA. Remains of one of the animals were recovered for examination.

NOAA scientists plan to embark on a new mission to a second, deeper area of the hole in August. That mission will consist of a team of scientists from Mote Marine Laboratory, Florida Atlantic University, Georgia Institute of Technology and the U.S. Geological Society, according to NOAA.

Researchers are interested in studying the seawater chemistry in the holes for its unique qualities.

PHOTO: Divers found two deceased smalltooth sawfish, an endangered species, at the bottom of Amberjack Hole.
Divers found two deceased smalltooth sawfish, an endangered species, at the bottom of Amberjack Hole. The deceased sawfish were intact enough to be collected for research, and Mote scientists quickly reported the discovery to NOAA and the Fish and Wildlife Conservation Commission and obtained the required permit for collection of one of the sawfish, a male measuring an impressive 12 feet long.
Mote Marine Laboratory via NOAA

"Little is known about blue holes due to their lack of accessibility and unknown distribution and abundance," NOAA said in a statement. "The opening of a blue hole can be several hundred feet underwater, and for many holes, the opening is too small for an automated submersible."

Researchers don’t know much about blue holes, but scientists are hoping to learn if the holes are connected to Florida’s groundwater or if there is groundwater intrusion into the Gulf of Mexico.

They're also looking to see if a particular blue hole is secreting nutrients or harbors microenvironments or new species of microbes.